Exclamation [Q] Google Play Store

This is what it happen . I downloaded and installed Fifa 14 and i noticed the wi-fi icon turned from blue to grey . didnt payed too much attention to that at that time. i wanted to install something else and gotthe 491 error . i did everything i could find on the net about that error ( cache clear , log off and in account , everything) i even flashed a new rom. on 3g connection everything is fine, on wi-fi google play gives me no connection error or 491 or just stops
can any of you tell me how to fix this? everything else works great on wifi except google services and i still got the grey wifi icon . i have other phones on that same router and everything works fine on those . i tried connecting to another wifi and still the same . i can install and update everything on 3g but not on wifi ... pls help